Arduinos, esp8266 and wemoses are brilliant for simple IoT tasks. The raspberry is ideal as a command & control server for that stuff. It isn't adding extra power to the pi it's offloading tedious workload to the microcontroller.

Rename with an mv command /boot/config.txt to /boot/config.txt~ then create a new empty one with touch /boot/config.txt Then reboot and see what happens. Most TVs can play nicely with a RPi with no junk in config.txt. Try another HDMI cable, more problems on here were due to broken or substandard ca...